During forwarding behavior of router data, some behaviors are normal and some are abnormal. For example, generally, there is a probability of packet loss in the forwarding process. Some packet loss behaviors are normal, for example, packet loss behavior caused by network congestion is normal, and packet loss behavior caused by the router discarding the data packet intentionally is normal. Some data packets should be forwarded and the router discards them for some unexpected reasons and this packet loss behavior is abnormal.
However, during the forwarding behavior of the router data, if the forwarding behaviors of the router date are inconsistent, this may cause problems, such as, network fail problem or network security problem. Therefore, during the forwarding process of data, how to determine whether the forwarding behavior is normal is important to verify consistence of the forwarding behaviors of the router data.